Guidance For 3D Printing Materials
3D printing material Types, Applications, and Attributes.
3D printing empowers you to prototype and manufacture parts for a wide range of applications quickly and cost-effectively. This comprehensive guide to 3D printing materials showcases the most popular plastic and metal 3D printing materials available, compares their properties, applications, and describes a framework that you can use to choose the right one for your project.
Plastic 3D Printing Materials and Processes
There are dozens of plastic materials available for 3D printing, each with its unique qualities that make it best suited to specific use cases. To simplify the process of finding the material best suited for a given part or product, let’s first look at the main types of plastics and the different 3D printing processes.
See below two main types of plastics:
- Thermoplastics are the most commonly used type of plastic. The main feature that sets them apart from thermosets is their ability to go through numerous melt and solidification cycles. Thermoplastics can be heated and formed into the desired shape. The process is reversible, as no chemical bonding takes place, which makes recycling or melting and reusing thermoplastics feasible. A common analogy for thermoplastics is butter, which can be melted, re-solidify, and melted again. With each melting cycle, the properties change slightly.
- Thermosetting plastics (also referred to as thermosets) remain in a permanent solid state after curing. Polymers in thermosetting materials cross-link during a curing process that is induced by heat, light, or suitable radiation. Thermosetting plastics decompose when heated rather than melting, and will not reform upon cooling. Recycling thermosets or returning the material back into its base ingredients is not possible. A thermosetting material is like cake batter, once baked into a cake, it cannot be melted back into batter again.
The three most established plastic 3D printing processes today are the following:
- Fused deposition modeling (FDM) 3D printers melt and extrude thermoplastic filaments, which a printer nozzle deposits layer by layer in the build area.
- Stereolithography (SLA) 3D printers use a laser to cure thermosetting liquid resins into hardened plastic in a process called photopolymerization.
- Selective laser sintering (SLS) 3D printers use a high-powered laser to fuse small particles of thermoplastic powder.
FDM 3D Printing
Fused deposition modeling (FDM), also known as fused filament fabrication (FFF), is the most widely used form of 3D printing at the consumer level, fueled by the emergence of hobbyist 3D printers.
This technique is well-suited for basic proof-of-concept models, as well as quick and low-cost prototyping of simple parts, such as parts that might typically be machined.
Consumer level FDM has the lowest resolution and accuracy when compared to other plastic 3D printing processes and is not the best option for printing complex designs or parts with intricate features. Higher-quality finishes may be obtained through chemical and mechanical polishing processes. Industrial FDM 3D printers use soluble supports to mitigate some of these issues and offer a wider range of engineering thermoplastics or even composites, but they also come at a steep price.
As the melted filament forms each layer, sometimes voids can remain between layers when they don’t adhere fully. This results in anisotropic parts, which is important to consider when you are designing parts meant to bear load or resist pulling.
Popular FDM 3D Printing Materials
The most common FDM 3D printing materials are ABS, PLA, and their various blends. More advanced FDM printers can also print with other specialized materials that offer properties like higher heat resistance, impact resistance, chemical resistance, and rigidity.
| MATERIAL | FEATURES | APPLICATIONS |
|---|---|---|
| ABS (acrylonitrile butadiene styrene) | Tough and durable Heat and impact resistant Requires a heated bed to print Requires ventilation | Functional prototypes |
| PLA (polylactic acid) | The easiest FDM materials to print Rigid, strong, but brittle Less resistant to heat and chemicals Biodegradable Odorless | Concept models Looks-like prototypes |
| PETG (polyethylene terephthalate glycol) | Compatible with lower printing temperatures for faster production Humidity and chemical resistant High transparency Can be food safe | Waterproof applications Snap-fit components |
| Nylon | Strong, durable, and lightweight Tough and partially flexible Heat and impact resistant Very complex to print on FDM | Functional prototypes Wear resistant parts |
| TPU (thermoplastic polyurethane) | Flexible and stretchable Impact resistant Excellent vibration dampening | Flexible prototypes |
| PVA (polyvinyl alcohol) | Soluble support material Dissolves in water | Support material |
| HIPS (high impact polystyrene) | Soluble support material most commonly used with ABS Dissolves in chemical limonene | Support material |
| Composites (carbon fiber, kevlar, fiberglass) | Rigid, strong, or extremely tough Compatibility limited to some expensive industrial FDM 3D printers | Functional prototypes Jigs, fixtures, and tooling |
SLA 3D Printing
Stereolithography was the world’s first 3D printing technology, invented in the 1980s, and is still one of the most popular technologies for professionals.
SLA parts have the highest resolution and accuracy, the clearest details, and the smoothest surface finish of all plastic 3D printing technologies. Resin 3D printing is a great option for highly detailed prototypes requiring tight tolerances and smooth surfaces, such as molds, patterns, and functional parts. SLA parts can also be highly polished and/or painted after printing, resulting in client-ready parts with high-detailed finishes.
Parts printed using SLA 3D printing are generally isotropic—their strength is more or less consistent regardless of orientation because chemical bonds happen between each layer. This results in parts with predictable mechanical performance critical for applications like jigs and fixtures, end-use parts, and functional prototyping.
Popular SLA 3D Printing Materials
SLA 3D printing is highly versatile, offering resin formulations with a wide range of optical, mechanical, and thermal properties to match those of standard, engineering, and industrial thermoplastics.
| FORMLABS MATERIALS | FEATURES | APPLICATIONS |
|---|---|---|
| Standard Resins | High resolution Smooth, matte surface finish | Concept models Looks-like prototypes |
| Clear Resin | The only truly clear material for plastic 3D printing Polishes to near optical transparency | Parts requiring optical transparency Millifluidics |
| Draft Resin | One of the fastest materials for 3D printing 4x faster than standard resins, up to 10x faster than FDM | Initial Prototypes Rapid Iterations |
| Tough and Durable Resins | Strong, robust, functional, and dynamic materials Can handle compression, stretching, bending, and impacts without breaking Various materials with properties similar to ABS or PE | Housings and enclosures Jigs and fixtures Connectors Wear-and-tear prototypes |
| Rigid Resins | Highly filled, strong and stiff materials that resist bending Thermally and chemically resistant Dimensionally stable under load | Jigs, fixtures, and tooling Turbines and fan blades Fluid and airflow components Electrical casings and automotive housings |
| Polyurethane Resins | Excellent long-term durability UV, temperature, and humidity stable Flame retardancy, sterilizability, and chemical and abrasion resistance | High performance automotive, aerospace, and machinery components Robust and rugged end-use parts Tough, longer-lasting functional prototypes |
| High Temp Resin | High temperature resistance High precision | Hot air, gas, and fluid flow Heat resistant mounts, housings, and fixtures Molds and inserts |
| Flexible and Elastic Resins | Flexibility of rubber, TPU, or silicone Can withstand bending, flexing, and compression Holds up to repeated cycles without tearing | Consumer goods prototyping Compliant features for robotics Medical devices and anatomical models Special effects props and models |
| Medical and dental resins | A wide range of biocompatible resins for producing medical and dental appliances | Dental and medical appliances, including surgical guides, dentures, and prosthetics |
| Jewelry resins | Materials for investment casting and vulcanized rubber molding Easy to cast, with intricate details and strong shape retention | Try-on pieces Masters for reusable molds Custom jewelry |
| ESD Resin | ESD-safe material to improve electronics manufacturing workflows | Tooling & fixturing for electronics manufacturing Anti-static prototypes and end-use components Custom trays for component handling and storage |
| Flame Retardant (FR) Resin | Flame retardant, heat-resistant, stiff, and creep-resistant material for indoor and industrial environments with high temperatures or ignition sources | Interior parts in airplanes, automobiles, and railways Custom jigs, fixtures, and replacement parts for industrial environments Protective and internal consumer or medical electronics components |
| Ceramic Resin | Stone-like finish Can be fired to create a fully ceramic piece | Engineering research Art and design pieces |
SLS 3D Printing
Selective laser sintering (SLS) 3D printing is trusted by engineers and manufacturers across different industries for its ability to produce strong, functional parts. Low cost per part, high productivity, and established materials make the technology ideal for a range of applications from rapid prototyping to small-batch, bridge, or custom manufacturing.
As the unfused powder supports the part during printing, there’s no need for dedicated support structures. This makes SLS ideal for complex geometries, including interior features, undercuts, thin walls, and negative features.
Just like SLA, SLS parts are also generally more isotropic than FDM parts. SLS parts have a slightly rough surface finish due to the powder particles, but almost no visible layer lines.
Popular SLS 3D Printing Materials
The material selection for SLS is limited compared to FDM and SLA, but the available materials have excellent mechanical characteristics, with strength resembling injection-molded parts. The most common material for selective laser sintering is nylon, a popular engineering thermoplastic with excellent mechanical properties. Nylon is lightweight, strong, and flexible, as well as stable against impact, chemicals, heat, UV light, water, and dirt.
| MATERIAL | DESCRIPTION | APPLICATIONS |
|---|---|---|
| Nylon 12 | Strong, stiff, sturdy, and durable Impact-resistant and can endure repeated wear and tear Resistant to UV, light, heat, moisture, solvents, temperature, and water | Functional prototyping End-use parts Medical devices |
| Nylon 11 | Similar properties to Nylon 12, but with a higher elasticity, elongation at break, and impact resistance, but lower stiffness | Functional prototyping End-use parts Medical devices |
| TPU | Flexible, elastic, and rubbery Resilient to deformation High UV stability Great shock absorption | Functional prototyping Flexible, rubber-like end-use parts Medical devices |
| Nylon composites | Nylon materials reinforced with glass, aluminum, or carbon fiber for added strength and rigidity | Functional prototyping Structural end-use parts |
Metal 3D Printing
Beyond plastics, there are multiple 3D printing processes available for metal 3D printing.
- Metal FDM
Metal FDM printers work similarly to traditional FDM printers, but use extrude metal rods held together by polymer binders. The finished “green” parts are then sintered in a furnace to remove the binder.
- Selective Laser Melting (SLM) and Direct Metal Laser Sintering (DMLS)
SLM and DMLS printers work similarly to SLS printers, but instead of fusing polymer powders, they fuse metal powder particles together layer by layer using a laser. SLM and DMLS 3D printers can create strong, accurate, and complex metal products, making this process ideal for aerospace, automotive, and medical applications.
Popular Metal 3D Printing Materials
- Titanium is lightweight and has excellent mechanical characteristics. It is strong, hard and highly resistant to heat, oxidation, and acid.
- Stainless steel has high strength, high ductility, and is resistant to corrosion.
- Aluminum is a lightweight, durable, strong, and has good thermal properties.
- Tool steel is a hard, scratch-resistant material that you can use to print end-use tools and other high-strength parts..
- Nickel alloys have high tensile, creep and rupture strength and are heat and corrosion resistant.
Alternatives to Metal 3D Printing
Compared to plastic 3D printing technologies, metal 3D printing is substantially more costly and complex, limiting its accessibility to most businesses.
Alternatively, SLA 3D printing is well-suited for casting workflows that produce metal parts at a lower cost, with greater design freedom, and in less time than traditional methods.
Another alternative is electroplating SLA parts, which involves coating a plastic material in a layer of metal via electrolysis. This combines some of the best qualities of metal—strength, electrical conductivity, and resistance to corrosion and abrasion—with the specific properties of the primary (usually plastic) material.
Framework for Choosing the Right 3D Printing Material
With all these materials and 3D printing options available, how can you make the right selection?
Here’s our three-step framework to choose the right 3D printing material for your application.
Step 1: Define Performance Requirements
Plastics used for 3D printing have different chemical, optical, mechanical, and thermal characteristics that determine how the 3D printed parts will perform. As the intended use approaches real-world usage, performance requirements increase accordingly.
| REQUIREMENT | DESCRIPTION | RECOMMENDATION |
|---|---|---|
| Low performance | For form and fit prototyping, conceptual modeling, and research and development, printed parts only need to meet low technical performance requirements. Example: A form prototype of a soup ladle for ergonomic testing. No functional performance requirements needed besides surface finish. | FDM: PLA SLA: Standard Resins, Clear Resin (transparent part), Draft Resin (fast printing) |
| Moderate performance | For validation or pre-production uses, printed parts must behave as closely to final production parts as possible for functional testing but do not have strict lifetime requirements. Example: A housing for electronic components to protect against sudden impact. Performance requirements include ability to absorb impact, housing needs to snap together and hold its shape. | FDM: ABS SLA: Engineering Resins SLS: Nylon 11, Nylon 12, TPU |
| High performance | For end-use parts, final 3D printed production parts must stand up to significant wear for a specific time period, whether that’s one day, one week, or several years. Example: Shoe outsoles. Performance requirements include strict lifetime testing with cyclic loading and unloading, color fastness over periods of years, amongst others like tear resistance. | FDM: Composites SLA: Engineering, Medical, Dental, or Jewelry Resins SLS: Nylon 11, Nylon 12, TPU, nylon composites |
Step 2: Transform Performance Requirements to Material Requirements
Once you’ve identified the performance requirements for your product, the next step is translating them into material requirements—the properties of a material that will satisfy those performance needs. You’ll typically find these metrics on a material’s data sheet.
| REQUIREMENT | DESCRIPTION | RECOMMENDATION |
|---|---|---|
| Tensile strength | Resistance of a material to breaking under tension. High tensile strength is important for structural, load bearing, mechanical, or statical parts. | FDM: PLA SLA: Clear Resin, Rigid Resins SLS: Nylon 12, nylon composites |
| Flexural modulus | Resistance of a material to bending under load. Good indicator for either the stiffness (high modulus) or the flexibility (low modulus) of a material. | FDM: PLA (high), ABS (medium) SLA: Rigid Resins (high), Tough and Durable Resins (medium), Flexible and Elastic Resins (low) SLS: nylon composites (high), Nylon 12 (medium) |
| Elongation | Resistance of a material to breaking when stretched. Helps you compare flexible materials based on how much they can stretch. Also indicates if a material will deform first, or break suddenly. | FDM: ABS (medium), TPU (high) SLA: Tough and Durable Resins (medium), Polyurethane Resins (medium), Flexible and Elastic Resins (high) SLS: Nylon 12 (medium), Nylon 11 (medium), TPU (high) |
| Impact strength | Ability of a material to absorb shock and impact energy without breaking. Indicates toughness and durability, helps you figure out how easily a material will break when dropped on the ground or crashed into another object. | FDM: ABS, Nylon SLA: Tough 2000 Resin, Tough 1500 Resin, Grey Pro Resin, Durable Resin, Polyurethane Resins SLS: Nylon 12, Nylon 11, nylon composites |
| Heat deflection temperature | Temperature at which a sample deforms under a specified load. Indicates if a material is suitable for high temperature applications. | SLA: High Temp Resin, Rigid Resins SLS: Nylon 12, Nylon 11, nylon composites |
| Hardness (durometer) | Resistance of a material to surface deformation. Helps you identify the right “softness” for soft plastics, like rubber and elastomers for certain applications. | FDM: TPU SLA: Flexible Resin, Elastic Resin SLS: TPU |
| Tear strength | Resistance of a material to growth of cuts under tension. Important to assess the durability and the resistance to tearing of soft plastics and flexible materials, such as rubber. | FDM: TPU SLA: Flexible Resin, Elastic Resin, Durable Resin SLS: Nylon 11, TPU |
| Creep | Creep is the tendency of a material to deform permanently under the influence of constant stress: tensile, compressive, shear, or flexural. Low creep indicates longevity for hard plastics and is crucial for structural parts. | FDM: ABS SLA: Polyurethane Resins, Rigid Resins SLS: Nylon 12, Nylon 11, nylon composites |
| Compression set | Permanent deformation after material has been compressed. Important for soft plastics and elastic applications, tells you if a material will return to its original shape after the load is removed. | FDM: TPU SLA: Flexible Resin, Elastic Resin SLS: TPU |
Step 3: Make a Selection
Once you translate performance requirements to material requirements, you’ll most likely end up with a single material or a smaller group of materials that could be suitable for your application.
If there are multiple materials that fulfil your basic requirements, you can then look at a wider range of desired characteristics and consider the pros, cons, and trade-offs of the given materials and processes to make the final choice.
Compare Plastic 3D Printing Materials and Processes
Different 3D printing materials and processes have their own strengths and weaknesses that define their suitability for different applications. The following table provides a high level summary of some key characteristics and considerations.
| FDM | SLA | SLS | |
|---|---|---|---|
| Pros | Low-cost consumer machines and materials available | Great value High accuracy Smooth surface finish Range of functional materials | Strong functional parts Design freedom No need for support structures |
| Cons | Low accuracy Low details Limited design compatibility High cost industrial machines if accuracy and high performance materials are needed | Sensitive to long exposure to UV light | More expensive hardware Limited material options |
| Applications | Low-cost rapid prototyping Basic proof-of-concept models Select end-use parts with high-end industrial machines and materials | Functional prototyping Patterns, molds, and tooling Dental applications Jewelry prototyping and casting Models and props | Functional prototyping Short-run, bridge, or custom manufacturing |
| Materials | Standard thermoplastics, such as ABS, PLA, and their various blends on consumer level machines. High performance composites on high cost industrial machines | Varieties of resin (thermosetting plastics). Standard, engineering (ABS-like, PP-like, flexible, heat-resistant), castable, dental, and medical (biocompatible). | Engineering thermoplastics. Nylon 11, Nylon 12, and their composites, thermoplastic elastomers such as TPU. |
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